package com.baseDemo.web.interceptors;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.log4j.Logger;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import com.baseDemo.web.entity.UserEntity;
import com.baseDemo.web.server.SystemServer;

public class LoginInterceptor implements HandlerInterceptor {
	private Logger logger = Logger.getLogger(getClass());
	//当有拦截器抛出异常时,会从当前拦截器往回执行所有的拦截器的afterCompletion() 
	@Override
	public void afterCompletion(HttpServletRequest arg0,
			HttpServletResponse arg1, Object arg2, Exception arg3)
			throws Exception {
		// TODO Auto-generated method stub
		
	}
	 //在业务处理器处理请求执行完成后,生成视图之前执行的动作   
	@Override
	public void postHandle(HttpServletRequest request, HttpServletResponse response,
			Object arg2, ModelAndView arg3) throws Exception {
		
	}
	/**
	 * 在业务处理器处理请求之前被调用
	 * 如果返回false
	 *     从当前的拦截器往回执行所有拦截器的afterCompletion(),再退出拦截器链
	 * 
	 * 如果返回true
	 *    执行下一个拦截器,直到所有的拦截器都执行完毕
	 *    再执行被拦截的Controller
	 *    然后进入拦截器链,
	 *    从最后一个拦截器往回执行所有的postHandle()
	 *    接着再从最后一个拦截器往回执行所有的afterCompletion()
	 */

	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
			Object handler) throws Exception {
		HttpSession session = request.getSession();
		UserEntity userEntity = (UserEntity)session.getAttribute(SystemServer.getInstance().get("USERSESSION").toString());
		if(userEntity==null){
			logger.debug("用户未登陆");
			request.getRequestDispatcher("login").forward(request, response);  
			return false;
		}else{
			return true;
		}
	}

}
